US scientists examine the secrets of a tasty tomato

Posted by AFN Staff Writers on 28th May 2012

US scientists claim they have identified exactly what makes for good tomato chemistry – including some aromas that give the perception of sweetness independent of sugars.

The scientists, from the University of Florida, say their research is “the first step to restoring good flavour in commercial tomatoes.”

Tomato flavour depends on sugars, acids, and a host of less well-defined aroma volatiles (so named for the ease with which they vaporize, sending scent molecules into the air).

Dr Harry Klee and colleagues at the University of Florida, set out to define the chemicals that are most important to our fondness for one particular tomato or another.

The researchers assembled chemical profiles of 278 tomato samples representing152 heirloom varieties, most of which were bred before the commercial tomatoes of today existed.

Dr Klee said, “The effort turned up an unexpectedly large chemical diversity within the heirloom tomatoes. That diversity presented us with an opportunity to really explore what makes consumers favour one tomato over another.”

They did a series of taste tests with a consumer panel using a subset of those heirlooms that represented the most chemical diversity. A statistical analysis of the chemistry and taste test results showed that flavour intensity traces to 12 different compounds and sweetness to another 12, including 8 that were also important for overall flavor.

Tomato volatiles found to give perception of sweetness

The researchers also found that some flavour volatiles influence the perception of sweetness through our sense of smell. “In other words,” Dr Klee said, “there are volatile chemicals unrelated to sugars that make things taste sweeter.”

The finding raises the possibility that this feature might be played up in tomatoes and other foods to make us experience no-calorie sweetness through our noses instead of our tongues.

The analysis also showed that some of the volatiles most abundantly present in tomatoes offer little in terms of our enjoyment of them in comparison to other and much more rare ingredients.